I mostly just play offline/splitcreen anyways...and the lack of splitcreen online support really killed the online experience for me...since almost ALL other multilayer games offer it...makes it so that my wife and I can play online without having 2 Xbox's...
IW wanted to price their map packs at $10 (which is still more than I would pay, but that is actually worth me thinking about it), Activision said $20, so they met in the middle...so they priced the 2nd one the same...
Also, it is becoming more and more easier to hack and bot online...seems like it is common to have a nuke go off within a minute of a match now -.-